386 PC compatible

Any Intel or compatible 386 or later microprocessor based PC compatible. See the entry for PC compatible below for more information. Note that on most of the DocsWare pages, this term is used to describe anything based upon the i80386 or later.

API

An acronym for Application Programming Interface. This is normally used to refer to the calls an operating system has provided to applications, but it is used loosely to describe any calls which are provided to an application from any point. For example, a disc cache could add a flush cache request to the disc API functions of DOS, and it would still be considered part of the disc API under this definition.

ATAPI

An acronym for AT Attachment Packet Interface, AT short for the IBM designation for 80286 or later computers PC-AT (which seems to come from the designation Personal Computer - Advanced Technology). ATAPI is an extension upon the IDE standard which allows removable medium drives, CD-ROMs, tape drives, or other devices to be attached to a 386 PC compatible computer on the same interface card as an IDE hard disc.

BIOS

There seems to be some debate as to whether this stands for Basic Input/Output System, or Built In Operating System. I tend to prefer the former, as it more accurately describes what function it performs. The BIOS on a PC compatible computer is the program in the computer's ROMs which tells the computer how to perform certain basic I/O tasks, such as writing to the display, reading the keyboard, accessing the disc drives, &c.

Boot sector

The boot sector on a floppy disc or hard disc partition contains the instructions needed to load the operating system from the floppy disc or partition. The boot sector on a hard disc partition is loaded by the hard disc's MBR; on a floppy disc the system loads the boot sector directly (this is because floppy discs can not be partitioned).

Boot manager

A program which controls the boot process. Normally, a boot manager would allow the user to choose which operating system to boot when the system starts, or some other system option which can only be chosen during the boot process.

Cardware

A variant of the shareware program distribution method. This method is normally used when the programmer simply wants to know how many people are using a program and what they think of it. Typically, cardware programs are simple utilities or games which the programmer just threw together for his own amusement, and was encouraged to distribute. See the entry on Shareware below.

CMOS

Actually, CMOS is an acronym for Complementary Metal Oxide Semiconductor. However, when used in the context CMOS settings on a PC compatible computer, it refers to the settings which the computer stores in the clock chip's battery backed CMOS SRAM. CMOS SRAM is used because of its low power requirements and simple support hardware. These settings are usually vital to the proper operation of the compuer; in many cases losing them means having to reconfigure the system.

Disc service request

The PC compatible class of computers uses a standard disc service request (often referred to by its assembly mnemonic, INT 13) to control the floppy and hard disc drives. This allows a standard set of disc requests to apply to a large number of possible disc devices, from floppy discs, to IDE hard discs, to SCSI hard discs, to just about anything capable of resembling a direct sector access device. Unfortunately, many a virus will take over this request, allowing it to infect any disc which a system touches while it is resident.

DRAM

An acronym for Dynamic Random Access Memory. DRAM is often the primary working memory of a system because it is usually cheaper (although slower) than SRAM, and much faster than storage devices (discs, drums, tapes, cards). DRAM often uses a muliplexed address bus, which means it can take several cycles to access a particular point, making it actually much slower than its rated speed. There have been many hacks for this through the years, including Fast Page DRAM, EDO DRAM, and SDRAM. Basic DRAMs often require four clocks to read or write a memory element (a bit in older systems, but modern memory busses are often 64 bits or wider).

EDO DRAM

EDO, an acronym for Extended Data Out, is a performance hack on Fast Page DRAM. EDO memories allow the data read/data write phase to occur while the next address is being loaded. This simplistic pipelining can reduce effective times from 4 clocks for initial and 3 for subsequent to 3 clocks for initial and 2 for subsequent cells, if it is used over long bursts. It still takes four clocks to access the first cell, but you can start specifying the second cell while reading the first, and so on.

ESDI

This is an acronym, but I can not find any official definition of it. ESDI was a hard disc interface standard which was based upon the register set from the MFM and RLL hard drives (Intel 82062 register set). There were many extensions to the 82062 standard which allowed for intelligent drive recognition, different data rates (drive or controller provided), and many other enhancements. Typically, ESDI drives were the high-performance drives of their day.

Fast Page DRAM

Fast Page DRAM is a form of performance hack on DRAM. Fast Page memories allow a page to remain active in the memory, so only one part of the address needs to be reloaded for subsequent accesses. This does not affect access to the initial cell (still four clocks), but it does make additional accesses in the same page take one clock fewer, so it now often takes only three clocks for these. If accesses cross a page boundary, the page will have to be reloaded, so then it takes four clocks again.

Freeware

Freeware is any program which has not been placed in the public domain (so the author retains full rights to it), but has no associated charge. Usually freeware programs are simple utilities or example code, but there are some freeware applications.

HTML

HyperText Markup Language. HTML is a standard by which hypertext documents can be written so they are able to be viewed using commonly available programs on just about any popular platform or operating system. You are looking at an HTML document right now!

Hypertext

Normal text documents contain only text or simplistic illustrations. Hypertext documents contain text as normal text documents, but also can contain links to various places within the document, even to other documents. Many hypertext document viewers these days support pictures, colours, even sounds(!) being embedded within documents.

IDE

An acronym for Integrated Drive Electronics (though some people claim it instead stands for Intelligent Device Enhancement). IDE is a hard disc standard derived from the old ESDI standard, primarily designed for PC compatible computers to communicate with hard discs. More recently, it has been extended to allow for other devices. These other decices are commonly referred to as ATAPI compliant.

MBR

An acronym for Master Boot Record. The MBR on a hard disc is a sector which contains the instructions which tell the computer how to locate the partition it is expected to boot. The MBR also contains the partition table. Replacing the MBR allows a program to take over how the computer boots a partition on the hard disc.

MFM

An acronym for Modified Frequency Modulation. MFM is an older method for encoding data on hard discs (it is still used on floppy discs). It also commonly refers to the class of hard disc, which typically allowed 17 sectors (512 data bytes each) per track on a 3600 RPM platter (top transfer rate of about 500KB per second).

Netscapism

The term Netscapism refers to a part of the HTML specification which is not commonly implemented, or is unique to the Netscape browsers (actually, many of these are optional or are not part of the specification). There are many Netscapisms (compare pages viewed with Netscape to the same page viewed in another browser), but only a few true Netscapisms which are implemented only by the Netscape browser. Many browsers strive toward being fully HTML compliant and including support for the more common Netscapisms.

PC compatible

Okay, so the purists will get me on this one, but I think that IBM compatible is at best a contradiction in terms, and this comes pretty close to being one. I use this term to describe any system based upon the Intel or compatible microprocessors, using any of ISA, MC, EISA, VL, PCI, or AGP busses for communication with peripherals. This is the platform which brought us the saying Standards are wonderful -- there are so many to choose from.

PnP (Plug and Play)

This is an ISA bus device standard which allows for software or firmware to detect which devices are present in a system and automatically configure them. PnP is not needed for other busses (MC, EISA, PCI, AGP) which implement their own resource management, and is not available on VL peripherals probably because VL effectively died off before the standard became available. PnP compliant firmware or software can often make simple configurations work, but will often cause problems when used in more complicated setups. There are also PnP-like specifications for EIA232 and IEEE1284 connected devices.

Registration code

This is a code which allows a shareware program to continue to function (or to enable a key function) once it has been registered. It is usually sent to the person who registered the program when the author receives the registration fee for the program. See the entries on Registration fee and Shareware below.

Registration fee

The is the sum of money which is paid to a shareware author to register his program. See the entry on Shareware below.

RLL

An acronym for Run Length Limited. RLL is an older method for encoding data on hard discs. It also commonly refers to the class of hard disc, which typically allowed 26 to 34 sectors (512 data bytes each) per track on a 3600 RPM platter (typical transfer between 750KB and 1000KB per second).

ROM

An acronym for Read Only Memory. ROMs are the chips which contain the instructions for the computer to test itself initially. On the PC compatible platform, the ROMs also contain the instructions to operate in `real mode' operating systems like DOS.

SCSI

An acronym for Small Computer Systems Interface (pronounced scuzzy, or at one time by Apple Computer, sexy). SCSI is a peripheral interconnect standard (derived at least partially from the old SASI, Shugart Associates Systems Interface) primarily designed for computer to peripheral connections (but can be used to connect two computers). It is a parallel interface, 8bit or 16bit or 32bit word width, with a transmission speed of up to 160 million words per second. It typically is used for mass storage hardware or other peripherals which require considerable bandwidth.

SDRAM

SDRAM, or Synchronous DRAM is a performance improvement often layered onto EDO DRAM. Synchronous memories operate synchronously with the system bus, meaning they are always in phase with the system bus. This eliminates stalls due to clock misalignment. Also, synchronous DRAMs seem to have another performance improvement : a way to access the next cell without having to reload any of the address (unless the next cell is not in the same page). This can take effective access times down to three clocks initially and one clock for subsequent cells.

Shareware

A program distribution method which allows users to examine and use the program before they decide to purchase it. Normally, the program may be used for a month or so before the user must either remove it from his system, or send the author some amount of money to register it. Typically a shareware program will either cease to function after some period of time or will have some key feature disabled if it is not registered, as a way to encourage people to register it.

SRAM

An acronym for Static Random Access Memory (compare DRAM). SRAM is normally high speed memory, with a non-multiplexed bus, which does not require refreshing (instead it uses a small but steady current to maintain data integrity). SRAM can be used in low power applications because it does not drain much current when it is idle, and does not require external support circuitry to maintain data integrity. SRAM is also used in caching DRAM because SRAM is often faster (even if it is rated the same speed, because of DRAM's multiplexed bus), but is also often rather more expensive. SRAMs only need one clock to access any memory cell.

Virus

The term virus refers commonly to any computer program designed to replicate, to corrupt data, to seek and destroy certain data or systems, to perform any similarly malicious act, or any combination of these. The term therefore is loosely defined as any program meant to do harm in some way to a system or its data (see a computer security journal for a more accurate definition, and while you are there, look up tapeworm and bomb also).

Web Bug

The term Web bug is commonly used to refer to an item placed on a web page for the purpose of monitoring the user's movement or other activity. A web bug is a more insidious device than a cookie, because it generally only requires a browser which tries to load the item, rather than requiring the browser be able to store cookies. A web bug is often an invisible image, one pixel by one pixel, which contains a link to another site. The other site assigns your browser an ID which is encoded in the timestamp of the image, and which is used to trace your movement, possibly across many sites. Web bugs can also be larger and visible, so any item on a page could be a potential web bug, especially if it links to another machine.

He

It is a real pity I have to put this here, but somebody would have to get mad if I did not include it. I do not use the rather awkward he/she or (s)he because I find them and similar constructs quite distracting. In cases I do not know the gender of a person to whom I refer in the third party, I use he as a generic term, per tradition.

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